A great site, I contributed a few links years ago and I'm happy to see how the site has grown.

I've tried to warn owners of the older conversions to 7.62 that some of the long range match ammo of today is far more potent than the ammo these rifles were intended to use (M80 Ball or similar with 48,000 CUP ), but seldom with any success. The NRA UK has also had difficulty in convincing shooters there that they may damage their rifles with some modern long range ammo.

PS
Some of the converted rifles were only proofed at 58,000 CUP when new, and some long range loads are in the neighborhood of 59,000 CUP.
The Birmingham Proof Authority and NRA UK have mandated re proofing of 7.62 NATO conversion rifles if used in competition, and instituted inspections of bore size and chamber neck dimensions which now must meet a minimum specification.